Variable condenser



Nov. 2, 1926. 1,605,723

G. W. HEATH VARIABLE CONDENSER Filed Oct. 11 1922 2 Sheets-Sheet 1 gwuzntoz George WfieaT/L.

Nov 2, 1926. 1,605,723

' I G. W. HEATH VARIABLE CONDENSEk Filed Oct. 11, 1922 2 Sheets-Sheep 2 (1' ewye ld/ferzfb,

Patented Nov. 2, 1926.

UNITED was meant enact.

GEORGE W. HEATH,-*OF EAST ORANGE JERSEY-,ASSIGNOR OF ONE-HALF TO ALFRED C. HEATH, OF EAST ORANGE, NEW JERSEY.

VARIABLE coNnEivsnR.

The invention relates in general to variable electric condensers, such as are designed for use with high frequency current and radio apparatus, and the invention specifically relates to certain improvements in that type of condensers which include a set of stator plates and two sets of rotor plates, one of which is designed to coact with the stator plates to provide a major control of 1 the capacitance and the other set of which is designed to provide a minor or micrometric variation in the capacitance. v r

i In such forms of condensers now known itis a usual practice to mount the main rotor plates on a centrally disposed shaft and by means of a control knob-positioned forwardly of the usual panel to control the adjustmentof the main rotor plates relative to their associated stator plates. The supplemental rotor plate or plates, is controlled by a centrallypositioned shaftat the forward end of which is a supplemental knob positioned within the outlines, of the main knob or its associated dial plate. This construction has been found to be objectionable in practice due among other reasons to the fact that it is difficult to adjust -both-knobs simultaneously when positioned in such close relation. Further, special means have to be taken to avoid. possibility of one shaft communicating its rotary movement to the other when one shaft is used as a bearing for the other. Another objection totheconcentric arrangement of the knobs and their associated shaftsis that the juxtaposition of the operators hand induces body capacity which becomes particularly objectionable after the main rotor plates have been set and an attempt .is made to, obtain a refinement of movement of supplemental plate shaft which is close to the main body of the condenser plates. 1 q

Accordingly,the primary object of the invention is to provide, a simplified form of variable condenser of thety'pc outlined and which will feature compactness with-convenient accessibility to the "COIfi/TOlfEIHQ a-HS EOT both the main andp the supplemental rotor plates,1which' will tend Y to minimize the"delcterious efiect ojf bodycapacity adjacent the mainxrotor plate when manip-i'ilating' for;;'micrometric adjustment; and wl'iich ivill?pr,ovide a construction by means of which the main and supplemental plate may be adusted'simultaneously and without theoperators hands interfering with each other.

Broadly, this feature of the, invention is attained by offsetting the control knobs and their associated shafts across-the face of the panel and with sufiicient clearance therebetween to permit'the manipulation of-one knob without interference from the hand manipulating the other and -the minimizing of connecting structural parts to attain compactness i Another object ofthe' inventionisto provide a simplified form of structurefor carrylngthe stator and rotor plates in which metallic structural parts outside ofthe condenser field, and which do not-contribute to the condenser plate surfaceyhavebeen minimized in bulk as far, as'practicable. =Incidental to this object it is a desideratum to provide smallshaft bearings disposed so that the rotor plate supported therein can be positioned with its aXisfiXed and in this way insure a close positioning of the rotor plates close to their associated stator plates and which will feature a minimizing of any tendencyof the plates to contact when the shaft or its associated bearings become worn. Broadly, this phase of the invention is at tained first, by using shafts of small diameters, preferably solid shafts which can be contained in relatively small bearings and second by journalling small cylindrical portions of thesolid shaft in spaced bearings.

Another object of the invention andparticularly applicable to the supplemental or fine adjustment plate or plates is to provide a manually actuatedcontrol which will feat ture a delicacy of adjustment of the rotor plates and a refinement of'operation so as to insure amicrometrical degree ofvariation in rotor plate position by a relatively gross movement ofthe-operators fingers engaging the controlling knob. a

This phase of the invention is attained by a ,multiplyin'g power drive betweena small finger controlled knob "actuating a small diameter-ed driving memberand the periphery of-the actuated rotor plate. In-=o11e-'for1n of the invention this takes the form of ajge'ar train which; features; the- Jutilizatioh of the largediameterediiotor plateas the 1asteletrain. The invention features a knob for the supplemental plate control which is of a size to best fit the fingers of the operator when actuating the margin of the same with a light but not very powerful force, and which V the actuated knob.

Another object of the invention is to provide in a device of this character, a terminal member adapted to engage the rotor shaft, and which will provide a large amount of friction to insure a good electric bearing; and which furthermore can be readily adjusted to increase the friction when desired and to take up wear on the shaft and friction member.

Various other objects and advantages of the invention will be in part obvious from an inspection of the accompanying drawings and in part will be more fully set forth in the following particular description of one form of mechanism embodying my invention, and the invention also consists in certain new and novel features of construction and combination of parts hereinafter set forth and claimed.

In the accompanying drawing showing embodiments ofmy invention Figure 1, is a frontelevation.

Fig. 2, is a side elevation partly in section.

Fig. 3, is a vertical section.

Fig. 4-, is a detail showing a supplemental plate and its pinion.

Fig. 5, is a section through the supplemental plate at its bearing.

Fig. (3, shows a stop collar for the rotor.

Fig. 7, shows the adjusting block for the rotor. shaft.

Figs. 8, 9 and 10 are details of the latter.

Fig. 11, shows the spindle for actuating the supplemental plate. Figs. 12 and 13 show a modification.

My supplemental plate can be used with various forms of condensers that include a rotor and a stator. In the form shown the stator comprises the series of plates 2 mounted between supporting plates 3 and 4 that are connected by suitable bars 5, with the plates 2 properly spaced. These plates 2 are usually in the form of a semi-circle with a center portion cut away at 5. I

The rotor is shown as comprising ashaft 7 on which are rigidly mounted rotor plates 7, that are also semi-circular but provided with the usual ln bportion or extension 8 to re ceive the shaft 7 This shaft is mounted to turn in the bearing plates 3 and at as shown, so that the rotor plates 7 will swing between the respective stator plates 2without contact H I yfihQWWlfih ,Q. 1.e at he bearing aseless .l9 ;i. ;h ;l? l 9.fi .theaeetere Pit may be suitably secured to the panel 10 of a cabinet, with the shaft 7 projecting through the panel, and a knob 9 fast on its outer end. By turning the knob the rotor plates will interleave with the stator plates and vary 7-;

provide a supplemental plate 12, that is mounted to swing on the shaft 7 so that it can be moved independent of the movement of the rotor plates. This plate is mounted to swing adjacent one or more of the stator plates, and as shown will swing between the end plate 11 and the adjacent plate 13 of the stationary plates. But this plate 12 could be mounted in any desired manner to permit it to swing between the two of the stator plates. As shown this extra plate 12 has a hub 14 that turns free on a collar 15 on the shaft 7, see Fig. 5.

I provide means for swinging this supplemental plate 12, and which means engages the margin or periphery of the plate. As shown I provide a spindle 15 that has a bearing in the supporting plate 1, and will project through the panel 10, see Fig. 2, to one side of the knob 9 that may be provided with the usual dial 39. This spindle carries a pinion 16 that engages the toother margin 17 of the plate 12, see Fig. 1. On the outer end of the spindle 15 is a knob 37, by turning which the pinion will cause the plate 12 to be given a turning movement at a much reduced speed on ac count of the difference in the size of the pinion and the gear portion of the plate 12. By this means a very fine adjustment of the supplemental plate can be obtained. lVith a device of this character, it will be clearly understood that the rotor is turned until the desired adjustment or tuning is obtained, and then the supplemental is turned to give a much finer adjustment, because the movement of the rotor shaft will shift all of the rotor blades, while with this attachment but one plate is moved and that by a very fine adjustment. The supple-mental plate 12 is shown as provided with an arm or extension 1, that is also toothed forming an extension of the toothed margin 17. This will permit the complete half of the revolution of this plate by the spindle and pinion.

The'rotor, since its plates are one-half of a circle in area, will not function when swung beyond ahalf revolution and it is customary to provide stops to limit this movement For this purpose I provide a vstop plate shown in Fig. 2 in the form of a disk or ring 19 that is placed on the shaft- 7 adjacent the bearing plate a, and is pro- ..vided with an ear 21 that extends into a disk surrounding the shaft'7. This plate is provided with a pair of cars and 4.0 on opposite sides, that engage a stop pin 22 on the shaft 7, see Fig. These ears are so positioned as to permit the rotation of the rotor from a position with the two sets of plates in register, to position in which they are out of register entirely.

In devices of this character the rotor must be put in circuit with a terminal and it is customary to have the rotor plates in metallic engagement with the shaft and to cause a strip on a supporting plate to engage the shaft so that the plates will be in circuit in all positions to which swung. I have provided a special form of terminal member for the rotor and which is adjustable to increase the frictional contact when desired and which will also perform the function of a brake or retarding device, so that the rotor will remain in any position to which swung for tuning adjustment and will be held in such position. As shown I provide a block containing a slot at projecting in from one end, with an aperture 25 crossing this slot. The block lSdl'lOllIlliEld on the plate 3 with the aperture arranged to engage the shaft 7 on the reduced end 26, see Fig. e. The block being split will serve to engage the shaft by a spring pressure to a certain extent and the portions of the block can be drawn together by an adjusting screw 27 passing through the two parts of the block. This block mounted on the supporting plate 3 by a bolt 28 that passes through the plate and engages a terminal arm 29, to which the conductor can be attached for the rotor. This block serves to insure a good contact with the rotor shaft at all times, and further provides a brake that will hold the shaft and rotor in all adjusted positions.

In 12 and 13 i show a means for impair-ting a very slow movement to the rotor by means similar to that employed for swinging the supplemental plate 12. In these views shown a stator and a rotor having plates 7. One of the plates d2 of the rotor is provided with a toothed margin, and also a toothed extension 4:1 that engages a pinion 16 on a shaft or spindle having a head all. These parts correspond to the spindle 15' shown in Fig. 2. By this means the rotor can be given a very fine adjustn'ient, and tuning can be effected with great ac uiacyq (that I claim is:

l. In a variable electric condenser, the combination of a main shaft, two sets of rotor plates carried by the shaft, one of said sets being fixed to the shaft to turn therewith and the other being loosely journalled on the shaft to turn independentlythereof, a Sec ond shaftat all times operatively connected to the other set of rotor plates to turn the same about the axis cit-the main shaft and sha said second shaft having its axis parallel to and cnfierent from the axis of the main shaft.

2. In a Vernier electric condenser, the coinbination with a plurality of plates grouped together to constitute a single setof stator plates and two sets of rotor plates operatively associated therewith, a pair of control "ts disposed in parallel and laterally spaced apart relation, with their axes eccentrically disposed, one of said shafts operatively connected to one of the sets of rotor plates and the other shaft similarly connected to the other set of rotor plates and said shafts being operably independent of each other whereby either set of rotor plates may lie-moved relative to the set of stator plates.

in an electric condenser, a unit comprising two setsof rotor plates, stator plates operatively associated therewith, a main coniii-oi shaft operatively connected with one of the sets to obtain a major variance of the rapacitance, said shaft provided with a hearing, and a second control shaft operatively connected to the other set of rotor plates to obtain a minor variance of the capacitance, s id second shaft provided with a bearing distinct from the bearing for the main shaft, the bearing for said second shaft being mounted for adjustable movement to make and break will the driving connection of said second shaft with its associated set of rotor plates.

4. In a variable electric condenser, the combination of a shaft, a rotor plate ournailed on said shaft and free to turn thereon and a control spaced from the shaft and in direct driving connection with the edge of the rotor plate for adjusting the same angularly about the axis of the shaft.

In a variable condenser, the combination of a support, a rotor plate loosely mounted on the support for rotary movement and having a circular peripheral portion with a relatively large radius, a control member mounted for rotary movement having a relatively small radius, s'aid rotor plate and said control member interengaging at their peripheral portions to provide a direct and multiple driving connection between the control member and the rotor plate.

(=3. In a variable condenser, the combination of a metallic rotor plate. mounted for retary movement and having a circular peripheral portion and a control member engaging the rotary plate at its peripheral portion and coacting therewith to provide a direct multiple driving connection between the metallic rotor plate and the control there for. I v

7. a variable condenser, the combination ofa metallic rotor plate mounted for rotary movei'n it and provided with concentrically disposed teeth, a control including a pinion in mesh therewith and providing a direct geared connection between the control and the rotor plate.

8. In a variable electric condenser, the combination with a stator plate, a rotor plate operatively associated therewith and mounted for rotary movement about an axis of rotation, a manually actuated control operatively connected to the plate and engaging the s ""e in radially spaced relation to its axis of rotation for angularly adjusting the rotor plate relative to its associated stator plate.

9. A rotor plate for variable electric condensers with a part its periphery circular, a portion of said periphery provided with teeth and the periphery at each end of the toothed portion providing extensions constituting stops too broad to be engaged by any pinion used to mesh with the teeth.

10. A rotor plate for variable electric condensers having a circular periphery roughcned to provide a driven surface adapted to be engaged by a driving member.

11. A substantially semi-circular rotor plate for variable electric condensers provided with a toothed periphery.

12. A rotor plate for a variable electric condenser comprising a flat metallic plate,

substantially semi-circular and provided with an extension from its peripheral portion, said extension forming a continuation of the peripheral edge whereby said edge will be more than 180.

13. In a variable condenser, the combination of a rotor plate substantially semicircular and journalled at its center for rotary movement, the peripheral portion of said plate provided with an extension, and a manually controlled member in driving engagement with the periphery of said semicircular portion and with said extension for turning the rotor plate over an angle of more than 180.

14c. In a variable condenser, the combination of a set of semi-circular stator plates fixed in position to form a condenser field, a plurality of semi-circular rotor plates adapted to be interleaved between the stator plates, one of said rotor plates provided with an extension adapted to project from said field when its associated plate is Within said field and means exterior of said field for engaging the extension to move the associated plate out of its position in the field.

In a variable electric condenser, the combination of a frame including a rear plate of insulating material, a rotor plate controlling and conducting shaft extending through the rear plate, a spring carried by the rear plate and bearing on the rear end of the shaft to shift the same axially, a split- .block of conducting material carried on the front side of the rear plate and providing a bearing and an electric contact for the shaft.

1('. In a variable electric condenser, the combination of a frame including a rear plate of insulating material, a rotor plate controlling and conducting shaft extending through the rear plate, a spring carried by the rear plate and bearing on the rear end of the shaft to shift the same axially, a split block of conducting material carried on the front side of the rear plate and pro riding a bearing, an electric contact for the sl ft, and an adjusting screw having L. readily accessible head and connecting the bifurcated portions of the split block to take up wear of the shaft in the bear' pro vided by the split block.

17. In a variable electric condenser, the c mbination of a solid metal rotor plate cont ol shaft provided at one end with a control lcneb and having its opposite end reduced, a pair of bearings, one of the parts adjacent the knob and the other for the reduced end, a split block formed of conducting material and providing a friction bearing engaging the reduced portion of the shaft and providing a frictional electrical connection with Mic shaft and a spring bearing on the reduced end of the shaft tending to move the same axially and providing an additional electric connection with the shaft.

in an electric condenser, the combina ion of a support, a control shaft extending through the support and provided with a stop pin, a stop member comprising an apertured disk encircling the shaft and proviced with a finger extending into the support and provided with a pair of cars for engaging the stop pin.

19. In a Vernier electric condenser, the con'ibination of two sets of rotor plates, a set of stator plates operatively associated with the two sets of rotor plates to form a unitary condenser, a pair of control shafts rotatable independent of each other, disposed in parallel and laterally spaced apart relation with their axes eccentrically disposed, one of said shafts operatively connected to one of the sets of rotor plates and the other shaft similarly connected to the other set of rotor plates.

20. In a device for producing electric condensing effects, the combination of two sets of rotor plates,,a set of stator plates, with the plates electrically connected to each other, and said set being operatively associated with the two sets of rotor plates, a pair of control shafts rotatable independent of each other, disposed in parallel and laterally spaced apart relation with their axes eccentrically disposed, one of said shafts operatively connected to one of the sets of rotor plates and the other shaft sin1ilarly connected to the other set of rotor plates.

21. In a variable electric condenser, the

I combination of a rotor plate and a stator plate operatively associated, said rotor plate tion of the pinion being parallel to and mounted for rotary movenient about an axis laterally spaced from the axis of rotation of of rotation, a rack and pinion drive for the rotor plate.

rotating said rotor plate and including a Signed at Newark, N. J., on October 5th, 5 substantially semi-circular rack secured to 1922.

the rotor plate and extending concentrically oi: its axis of rotation and the axis of rota- GEORGE W. HEATH. 

